The invention discloses a yarn tension device integrating elasticity with inertia load and a control method for the yarn tension device. The yarn tension device comprises a yarn tension applying device and an intelligent control system, wherein the yarn tension applying device is simultaneously connected with an elastic device and an inertia load device; the elastic device comprises a step motor and an elastic structure; the inertia load device comprises a connecting rod; one end of the connecting rod is connected with a counterweight; the other end of the connecting rod is fixed; and the step motor drives the step motor to control the balance position of the counterweight and the elastic structure. The yarn tension device disclosed by the invention realizes real-time control on tension, in a winding process, of a grooved drum winder, and density of produced cone yarns for dyeing on the same spindle and density of the produced cone yarns for dyeing on different spindles are uniform; and moreover, cone yarns with special requirements (for example requirements of being inside tight and outside loose) can be provided, forming is better and spindle length is more accurate.